It's tire time. I have a 03 3500 2WD Nothing fancy other than air bags and a sway bar. Front end was completely rebuilt 2 years ago. MM3 Beta Tuner
I am replacing the 4 tires on my truck. I get them pretty cheap from a fellow engineer who went to tires. My goal is to lower the RPM about 100+ at highway speed. This thing feels like it needs another gear. @F350Cummins agrees with that. It's also time to get all 4 the same.
I already have 3.42 rear gears. The engine sweet spot is between 1500 and 1600
I found a formula to figure it out, but of coarse, cost is a factor. https://www.ringpinion.com/calculators/Calc_RPM.aspx
265/70/17 31.6 tall 1762 RPM at 70 MPH 10.7 wide (1655 RPM at 65)
285/70/17 32,7 Tall 1722 RPM at 70 MPH 11.5 wide (1599 RPM at 65)
285/75/17 33.9 Tall 1661 RPM at 70 MPH 11.3 wide 2.3" taller than stock (1542 RPM at 65)
315/70/17 34.3 Tall 1637 RPM at 70 MPH 10" wide 2.8" taller (1520 RPM at 65)
The 315's offer the lowest RPM, but almost 3" taller. Since this is 2 wheel drive, I'm not as high as you other guys. I am concerned about rubbing. The 315's offer the best payback and the narrowest tread. Not sure the the stock rims can handle the 315's either. I'm going to turn the wheels and measure the clearance.
I'm looking for opinions/ideas/suggestions before I pull the trigger. $1000 doesn't come easy here.
@Double R Diesel Does the MM3 have tire size adjustment? I never looked
Probably the last set of tires I will ever buy.
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